The present disclosure relates generally to electrical distribution systems, and particularly to Automatic Transfer Switches.
Electrical distribution systems employ a variety of devices for controlling and managing the distribution of electrical power, including Automatic Transfer Switches. In general, an Automatic Transfer Switch (ATS) is a device that connects one of two power sources to a load, so that the load may receive electrical power in the event that one of the power sources becomes non-operational. Such devices are often employed in applications requiring emergency backup power generation, such as hospitals for example, where the primary source of power comes from a utility grid, and the alternate source of power comes from a backup generator. Many of the known ATSs employ electromagnetic switching relays coupled with rectifiers to provide control power and signaling to operate the switch of the ATS system. In these types of systems, the rectifier converts AC power to DC control power, and the electromagnetic relay provides the switching signals. In standard transition ATSs, that is, where the switch is connected to either one source or the other, a minimal number of components are required in order to provide the appropriate switching signals. However, in more complex systems, such as open transition ATSs where the switch of the ATS may be placed in an isolation position, a greater number of control components are required, which results in an ATS that requires additional real estate and wiring, thereby increasing the size and cost of the ATS. Also, due to the switching characteristics of electromagnetic relays, preventative maintenance of the ATS system is periodically required.
Accordingly, there is a need in the art for an ATS arrangement that overcomes these drawbacks.